Need help with HTTP Post/Get in an applet/servlet environment

I heed help with HTTP POST/GET in a client/servlet environment.  I want to write a Java client and servlet.  They will communicate via HTTP to POST/GET XML documents.  

This is using Apache Tomcat on the server side.

I have the start a client and servlet code.  My client applet can connect to the my server using this string:  ("http://localhost:8080/IPCServer");

IPCServer is the name of my servlet.  By using my browser and entering the connection string, I get a response from my servlet - it puts out some HTML to the browser.  However, I can't get my servlet to respond to my client applet.  Below is the code in my applet.  What am I doing wrong?  

            urlConn.setUseCaches(false);
            urlConn.setAllowUserInteraction(false);

            //urlConn.setRequestProperty("User-Agent", "BlackBerry");
            //urlConn.setRequestProperty("Accept_Language","en-US");

            //Content-Type is must to pass parameters in POST Request
            //urlConn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
            urlConn.setRequestProperty("Content-Type", "text/xml");
            urlConn.setRequestMethod("POST");

            String testData = URLEncoder.encode("This is my test data", "UTF-8");

            OutputStreamWriter out = new OutputStreamWriter(urlConn.getOutputStream());

            out.write("string=" + testData);
            out.flush();
            out.close();